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Quantum chemical studies on the molecular structure, spectroscopic and electronic properties of (6-Methoxy-2-oxo-2H-chromen-4-yl)-methyl pyrrolidine-1-carbodithioate

Evecen M., Tanak H.

Materials Science Poland

2016

Vol. 34, No. 4

886--904

In this paper, the molecular geometry, vibrational frequencies and chemical shifts of (6-Methoxy-2-oxo-2H-chromen-4-yl)methyl pyrrolidine-1-carbodithioate in the ground state have been calculated using the Hartree-Fock and density functional methods with the 6-311++G(d,p) basis set. To investigate the nonlinear optical properties of the title compound, the polarizability and the first hyperpolarizability were calculated. The conformational properties of the molecule have been determined by analyzing molecular energy properties. Using the time dependent density functional theory, electronic absorption spectra have been calculated. Frontier molecular orbitals, natural bond orbitals, natural atomic charges and thermodynamical parameters were also investigated by using the density functional theory calculations.

Deuterium Isotope Effects of 0-Hydroxythioamides, Thiazolines and 5-Acyl-2-thiobarbituric Acids

Hansen P., Duus F., Neumann R., Wesolowska A., Sosnicki J., Jagodzinski T.

Polish Journal of Chemistry

2000

Vol. 74, nr 3

409-420

Deuterium isotope effects on 13C chemical schifts are studied in a series of o-hydroxythioamides, 2 delta-thiazolines and enolic 5-acyl-2-thiobabituric acids. Novel 2-hydroxy-1-thiocarboxamide naphthalenes show steric isotope effects of opposite sign to those observed in 2-hydroxy-1-acetylnaphthalenes and pyrenes. The o-hydroxyaromatic 2delta-thiazolines show tautometric behaviour and accordingly large isotope effects. Tautomerism of these and the thioamides are discussed in relation to structure. Intramolecular hydrogen bonding of non-RAHB type show only weak effects. The enolic mono N-alkyl 5-acyl 2-thiobarbituric acids show two isomers, both of which are involved in enol-enol tautomerism.

Various amino protecting groups influence on 1H and 13C chemical shifts in a 2-deoxy-2-amino glucopyranoside

Olsson L., Jia Z., Fraser-Reid B.

Polish Journal of Chemistry

1999

vol. 73 nr 7

1091-1097

One glycoside, pent-4-enyl 2-amino-3, 4-di-O-benzoyl-6-O-t-butyldimethylsilyl-2-deoxy-B-D-glucopyranoside (1), has been derivatized at the amino function into five related compounds: ammonium trifluoroacetate, N-acetyl, tetrachlorophthalimide, phthalimide and azide. The 1H and 13CNMR spectra of these compounds have been fully assigned and compared. Significant influence on the chemical shifts given by the amino functionality can be found in the pyranosidic ring at position 1, 2 and 3. Only minor variations were found throughout the remaining positions.